Year	Percent
1990	93.296
1991	93.103
1992	92.466
1993	92.266
1994	91.624
1995	91.741
1996	91.589
1997	91.081
1998	90.825
1999	90.434
2000	90.22
2001	90.136
2002	90.174
2003	89.843
2004	89.879
2005	90.325
2006	90.342
2007	90.79
2008	90.932
2009	90.352
2010	90.559
2011	90.604
2012	90.131
2013	90.137
2014	89.869
2015	90.312
2016	90.157
2017	90.179
2018	90.201
2019	90.22
2020	90.236
2021	90.247
2022	90.256
2023	90.263
2024	90.27
2025	90.276
2026	90.28
2027	90.282
2028	90.282
2029	90.278
2030	90.27